Which isoenzyme of ALP is most heat stable?

The isoenzyme of alkaline phosphatase (ALP) that is most heat stable is the placental ALP. Heat stability is an important characteristic that can help differentiate various ALP isoenzymes in clinical settings. Placental ALP, found primarily during pregnancy and in placental tissue, exhibits greater resistance to heat compared to other isoenzymes such as liver, bone, and intestinal ALP.

This property is particularly useful in laboratory diagnostics, where heat treatment can help remove other isoenzymes that might interfere with specific tests. Thus, identifying placental ALP as the most heat-stable isoenzyme aids in effective analysis and interpretation of ALP levels within different clinical contexts.